The present invention relates to a field emission display (FED) driver, and more particularly, to a field emission display (FED) driver which has a constant pixel luminescence characteristic throughout a display.
Generally, flat panel displays adopt a matrix driving method according to their structural characteristics, and an amplitude modulation method or a pulse width modulation method is used for a gray scale implementation.
A field emission display (FED) uses both modulation methods. However, since the pulse width modulation method has a limit in implementing a gray scale, the amplitude modulation method is mainly used.
FIGS. 1A and 1B are circuit diagrams of a conventional FED driver, in which FIG. 1A shows an FED driver adopting an amplitude modulation method, and FIG. 1B shows an FED driver adopting a pulse width modulation method.
Referring to FIG. 1A, an input video signal is radiated onto the respective pixels of a display 7 constituted by an FED via an amplifer 3 for amplifying a video signal and a sample-and-hold circuit 5 for sampling according to a sampling rate and storing (holding) the sampled information to display the video signal amplified by the amplifier 3, thereby generating an image. In the FED driver shown in FIG. 1A, a biasing power source 9 creating a field emission is serially connected to ground.
As described above, an FED driver circuit which uses the amplitude modulation method is complicated, and does not have a standard integrated circuit. In addition, although the characteristic of each pixel may be different and a defective pixel may be generated, a compensating circuit is not provided.
Referring to FIG. 1B, an input video signal is converted into a digital signal by an analog-to-digital (A/D) converter 13. The digital signal is radiated into the respective pixels of a display 17 constituted by an FED via a pulse width modulator 15, thereby generating an image. However, since the pulse width modulation method is limited in the gray scale it can implement, the FED driver adopting this method shown in FIG. 1B cannot satisfy a delicate scale implementation, displaying an image with the delicate pixel differences and inherent characteristics of each pixel, similar to the FED driver adopting the amplitude modulation method. Also, since the compensation of a defective pixel is not performed, the circuit life is shortened.